Virtually any type of machine or mechanism undergoes at least one assembly step during its manufacture. And making a complex machine such as a motor vehicle may involve hundreds or even thousands of separate assembly steps.
Using a motor vehicle as an example, such vehicle has many subassembly units which are brought together on the final assembly line to make the finished vehicle. And to complete each subassembly unit, several component parts need to be brought together. An instrument panel unit is a good example.
One known approach to making an instrument panel unit involves providing a support structure, e.g., a frame, and attaching panel components to such structure and to one another. Frequently, close fitting of such components to one another is required to avoid unsightly gaps in the instrument panel unit.
Many of the components have a surface which is exposed to view in the finished vehicle and care must be taken to avoid chipping, gouging and marring of such surface. Surface impairments detract from the aesthetic quality of the vehicle and make the vehicle more difficult to sell. And such surface impairments can have a significant adverse impact upon after-sale warranty costs.
But unless a high degree of care is taken by persons on the assembly line, such exposed surfaces do become chipped or otherwise disfigured. Damage such as chipping or gouging occurs as components are being fitted to one another. And an inadvertent slip of a screwdriver or other assembly tool can scratch or dent a finished surface exposed in the completed vehicle.
Manufacturers usually strive to make vehicles that have very high mechanical and aesthetic quality. When an exposed surface becomes chipped or marred during the assembly process, there is little choice but to rework the unit, e.g., an instrument panel unit, either on the assembly line or after the vehicle is sold.
And some components cannot be repaired, at least not on the assembly line. As an example, the manufacturer must replace (not repair) an air bag assembly on which the exposed surface of the frangible cover is damaged. For reasons relating to the integrity of such assembly and the important safety feature that an air bag assembly may be called upon to perform, it is impermissible to repair such assembly. Scrap costs are high and overhead labor costs, either on the assembly or at the dealership, are very significant.